CNN Money: Top business headlines for Sept. 26

NEW YORK (CNN) -- CNN Money's Maribel Aber has your top business and financial news on this Thursday, September 26.

Debt ceiling crunch no later than Oct. 17
Treasury to Congress: The heat's on to raise the country's debt ceiling. Treasury Secretary Jack Lew said Wednesday he now estimates he will have less cash on hand to pay the country's bills in mid-October than he previously thought. Instead of the $50 billion he estimated a few weeks ago, he now thinks the cash balance will be closer to $30 billion. "This amount would be far short of net expenditures on certain days, which can be as high as $60 billion," Lew said in a letter to lawmakers.

Federal workers: Hand over BlackBerry during shutdown
Federal workers could soon be asked to turn in their government-issued BlackBerries and iPhones. That's because if the government shuts down next Tuesday, furloughed federal workers could be violating the law if they do something as simple as check their work e-mail. The Antideficiency Act, passed by Congress during Chester Arthur's administration, prevents non-working federal employees from doing any job-related functions during a shutdown if the government cannot pay for it.

How income inequality hurts America
It's not just income inequality. It's lifespan inequality. And education inequality. And declining economic growth. It's a well-established fact that the rich are getting richer, while the poor and middle class are falling behind. "The 400 richest people in the United States have more wealth than the bottom 150 million put together," said Berkeley Professor and former Labor Secretary Robert Reich on a recent CNNMoney panel on inequality. Meanwhile, the median wage earner in America took home 9% less last year than in 1999.

Postal Service seeks to hike stamp prices by 3 centsMailing a letter would cost three cents more, or 49 cents, starting in January, under a Wednesday proposal by the U.S. Postal Service. The price of sending a postcard would also go up by a cent to 34 cents. The rate hikes are expected to raise $2 billion for the cash-strapped postal service. The Postal Service must first get the approval of its regulatory panel, Postal Regulatory Commission, before it can raise prices over the rate of inflation.